Prior to catching on with everyone as the new tactical "must-have" and prior to the 5.11 subsidiary company designation, the 5 pocket khaki Royal Robbins pants were (and probably still are) issued to FBI and other Federal agency firearms instructors. As stated, they were originally designed for rock-climbing and prior to becoming so popular were available only direct from Royal Robbins and a few specialty climbing stores. I have both the original Royal Robbins and the new 5.11 version. They are identical in fit and configuration, except that I find the original with the Royal Robbins tag to be more durable. My Royal Robbins pairs that are sevral years older have been subjected to much more rigorous training and have held up better than the newer 5.11s that I have. That being said, the new 5.11s are still probably more durable than anything else you'll find.